package com.wasion.gydpe.common.security;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;

/**
 * 
 * @ClassName: LocalFilterSecurityInterceptor
 * @Description: 自定义过滤器：通过IoC生成securityMetadataSource
 * @author 高意
 * @date Oct 15, 2012 3:07:50 PM
 * 
 */
public class LocalFilterSecurityInterceptor extends AbstractSecurityInterceptor
		implements Filter {

	// 与applicationContext-security.xml里的localFilter的属性securityMetadataSource对应，
	// 其他的两个组件，已经在AbstractSecurityInterceptor定义
	private FilterInvocationSecurityMetadataSource securityMetadataSource;

	public void setSecurityMetadataSource(
			FilterInvocationSecurityMetadataSource newSource) {
		this.securityMetadataSource = newSource;
	}

	public FilterInvocationSecurityMetadataSource getSecurityMetadataSource() {
		return this.securityMetadataSource;
	}

	public SecurityMetadataSource obtainSecurityMetadataSource() {
		return this.securityMetadataSource;
	}

	public Class<? extends Object> getSecureObjectClass() {
		return FilterInvocation.class;
	}

	public void destroy() {
	}

	public void init(FilterConfig filterConfig) throws ServletException {
	}

	// ~ Methods
	// ========================================================================================================
	/**
	 * 发出请求时，被该过滤器拦截 Method that is actually called by the filter chain. Simply
	 * delegates to the {@link #invoke(FilterInvocation)} method.
	 * 
	 * @param request
	 *            the servlet request
	 * @param response
	 *            the servlet response
	 * @param chain
	 *            the filter chain
	 * 
	 * @throws IOException
	 *             if the filter chain fails
	 * @throws ServletException
	 *             if the filter chain fails
	 */
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {

		FilterInvocation fi = new FilterInvocation(request, response, chain);
		invoke(fi);
	}

	public void invoke(FilterInvocation fi) throws IOException,
			ServletException {

		InterceptorStatusToken token = super.beforeInvocation(fi);
		try {
			fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
		} finally {
			super.afterInvocation(token, null);
		}
	}

}